The invention relates generally to image projection systems, and more particularly to laser based projection systems for use in arenas, theaters, etc.
Various systems have been proposed and some are commercially available for producing a large color image, be it graphic and/or text onto a viewing panel for entertainment or informational purposes. One type of system employs a matrix or array of large colored incandescent lamps, each establishing a pixel of the image, and which are driven, e.g., energized and deenergized by a control system. While such systems are generally suitable for their intended purposes they nevertheless exhibit various drawbacks or limitations. For example such systems are necessarily large and complex, require substantial power, are expensive to operate and maintain, and are not generally suitable for producing complex, high resolution images. Optical fiber-based projection systems have also been proposed. While such systems may offer some advantages over the incandescent lamp based systems they still leave much to be desired from the standpoint of complexity, size, and particularly inability to produce complex, high resolution images.
Systems using laser devices to project a large scale image onto a surface have been proposed and some are commercially available. Such systems typically make use of computercontrolled vector scanning techniques to project a static or dynamic color image onto some surface, e.g., a wall. The following companies produce and sell such systems: Laser Media, Inc. of Los Angeles, Calif., Image Engineering, Inc. of Springfield Mass., Science Faction of New York, N.Y., Laser Fantasy of Redmond Calif., and Laser Images of Los Angeles, Calif.
Owing to the inherent limitations of vector scanning the prior art laser projection systems have been somewhat limited in the type of images produced thereby. In particular such images have tended to be line art. However, development is underway of laser projection systems utilizing raster scanning to thereby produce the type of complex, high resolution images presently produced by conventional television. Thus, the future is ripe for the implementation of laser based projection systems.
The ability to project a laser image onto a floor or some other surface in an arena or other facility is of considerable desirability and could soon become an ideal means of preprogrammed or real time communication for the sporting and special event audience. In this regard sponsor logos, team logos, mascots, animation, advertising, and other visual effects could be projected for ready visibility by the audience during pregame time, during timeouts, etc. However, if the laser projection system is to be used in such applications, since persons could intrude into the area in which the laser beam(s) is(are) projected they may be subjected to potential injury from the projected beam(s). Heretofore prior art laser projections systems have avoided that potential problem by confining the use of such systems to applications wherein the laser light is projected into a space which is not accessible by the public.
Accordingly, the need exists for a projection system suitable for projecting a laser-based image into an area which is accessible by the public, yet which is safe and meets the requirements of the Bureau of Radiological Health (BRH) of the FDA regarding exposure of persons to laser light.